An Afghan policeman receives a ballot paper at a polling station in Jalalabad east of Kabul on June 14, 2014. / Rahmat Gul, AP

by Luigi Serenelli and Shirzad Ashoori, Special for USA TODAY

by Luigi Serenelli and Shirzad Ashoori, Special for USA TODAY

KABUL - Dozens were killed in attacks nationwide as Afghans headed to the polls Saturday to elect a president who will help manage the exit of American troops from the country and lead the nation's fight against a resurgent Taliban.

Nearly 50 people were killed as more than 7 million of Afghanistan's 12 million eligible voters headed out for the election, a turnout of about 60%, Afghan officials announced at a news conference after polls closed.

Voters were choosing between former foreign minister Abdullah Abdullah and former finance minister Ashraf Ghani in a runoff election that represents the first transfer of power since U.S.-led NATO troops invaded the country shortly after the Sept. 11, 2001, terrorist attacks.

Abdullah Abdullah, a former leader of the Northern Alliance that fought against the Taliban's extreme Islamist rule, led the first ballot in April with 45% of the vote, while Ghani received 31.6%.

As the polls opened, some Afghans worried an Abdullah victory could widen fractures among an already ethnically divided population. Abdullah is an ethnic Tajik, not a member of the Pashtun tribe that comprises around 42% of the country's population.

"If Abdullah wins this election, he could play a role in increasing the hostility between the north and the south of the country, where mostly Pashtuns live," said Ziarmal Nangyaal, a 40-year-old Pashtun shopkeeper in Kabul.

Gul Rahman, 47, of Kabul said he would vote for Ghani because he is "an educated man" - the candidate has a doctorate in economics.

"Ghani's not like Abdullah, just a warlord man who is involved with all former mujahedin leaders," he said. "If Abdullah wins, all the government (ministries) will be staffed with his former commanders - and Afghanistan will again face adversity and poverty as it did during the war."

The first round of voting was a desire for change and a vote against current Afghan President Hamid Karzai, a Pashtun who at the time did not support Abdullah, analysts said. Now, however, the dynamic is changing as Abdullah appears to be solidifying his support. The Afghan president hasn't publicly supported either candidate, but his brother Mahmood Karzai backs Abdullah.

"In the second round, things have reoriented," said Sarah Chayes, an expert in South Asia policy at the Carnegie Endowment in Washington, D.C. "Karzai has gotten behind Abdullah."

Still, whoever wins will face questions about legitimacy that have dogged Karzai since he was installed after U.S.-led NATO forces toppled the Taliban nearly 13 years ago.

"There was an enormous amount of fraud in the first round, so people are disenchanted," said Chayes. "The result of the second round is likely to be seen as not accurately representing what people wanted."

The Taliban's success in controlling remote regions of the mountainous country and pulling off sporadic attacks in the capital, Kabul, have also eroded Karzai's popularity.

"The state can probably hold on to its authority if by 'hold on' you mean keeping control of Kabul," said Omar Hamid, a Central Asia expert at IHS London. "But whether the state will be able assert its authority or its presence in the rest of the country is still very, very questionable."

Afghanistan's next president will also have a tough job retaining the confidence of the international community.

The United States has spent almost $60 billion to support Afghan security forces and to counter the illicit narcotics trafficking in the region between 2002 and 2013, according to the U.S. Government Accountability Office.

But Karzai and American officials have failed to reach an agreement on bilateral security as U.S. and NATO troops strength dropped from 142,500 in mid-2011 to around 50,000 today. Lack of progress in the negotiations has soured donors who now provide crucial aid to the country.

"It is very likely that those donor nations may cut their aid budgets," said Hamid. "If that were to happen, it would of course be disastrous. The minute any kind of issue with paying salaries pops up with reference to the Afghan security forces, you'll see mass desertions."

President Obama plans to reduce the U.S. troop presence from 32,000 to 9,800 by year's end and withdraw all but a small security contingent by the end of 2016. NATO combat troops also plan to reduce their presence.

In a statement released Saturday, the White House commended the election process, adding that the administration looks forward to working with the next government.

"These elections are a significant step forward on Afghanistan's democratic path, and the courage and resolve of the Afghan people to make their voices heard is a testament to the importance of these elections to securing Afghanistan's future," the statement said.

Afghan voters said Abdullah would need to take a hard line on the country's challenges.

"I am afraid that if he wins, the enemies of our country - the Taliban, Pakistan and others - will probably create complications for Afghanistan," said Mukhtar Ahmad, 33, who works in a Kabul electronics shop.

Chayes echoed Ahmad's sentiments.

"Abdullah would be stepping into a position upon which enormous pressures are placed," he said. "The question is whether he is made of the right metal and force of character to withstand those pressures."